Frost is in the air!

This post was originally published on RETROactive on October 31, 2012. However, since we live in Alberta, this topic is almost ALWAYS relevant – what to do about frosty windows!

With winter coming, some owners of historic places might be witnessing the formation of frost on their single pane wood windows and storms, most notably on the second storey. The reasons for this will vary and subsequently so will the solutions. Generally speaking, a little frost now and again should not harm the window frame but a more persistent formation will saturate the surrounding material and, in the long run, potentially cause significant damage. Should this be the case, ignoring the situation is far from the recommended solution.

Frosty window. Note the closed storm window vent cover. During the winter it should be open.

So what is one to do?  The first step, as with any intervention on a historic place, is to develop an understanding of the problem.  What is causing frost to form on the window? The answer: warm moist air comes in contact with the cold glass and condenses, which then freezes on the surface. So how does one mitigate this? Should you let the house freeze so that the interior temperature matches the outside, or should you turn the house into an oven to eliminate any and all moisture in the air? Obviously, neither scenario is plausible.

So what is one to do – replace the windows?  Speaking from a heritage conservation perspective, replacing authentic historic windows would be the equivalent to someone shaving their head bald because they found a grey hair. Historic windows have, in my experience, proven themselves to be longer lasting than any modern window and can continue to serve their function with proper care and maintenance, while modern windows wear out and routinely need to be replaced.

As air moisture is the general cause of frosted windows, controlling it would appear to be the most appropriate approach. However, there is more than one way to control moisture during the winter. One can control moisture levels with a dehumidifier, or by preventing it from reaching the cold glass with weather stripping techniques. As well, one could better manage the presence of moisture with exhaust fans and insulation. Any combination of these efforts will help to reduce the frost on windows but it should also be noted that there are pre-existing systems that should be taken advantage of in regards to this problem.

Storm windows traditionally have three holes at their bases with a flap cover. During the winter, these should be open to let moisture and condensation escape. When bugs arrive with spring, close the flap. Double hung windows generally have locks where the sashes meet – use them to tighten the window and reduce air leakage. Should you decide to proceed with a form of weather stripping, concentrate on the interior side of the window and allow the storm window to breathe. This will create a micro-climate (similar to the ventilation in one’s roof), which should help prevent frost and therefore better sustain and protect the window.

Hopefully, the preceding information will be useful for those who might be dealing with frosty windows. There are many articles on the Internet, which tackle this issue and propose similar, different and additional solutions ranging from “free to expensive”.  As a Heritage Conservation Adviser, my advice, and that of the Standards and Guidelines for the Conservation of Historic Places in Canada, is to start with the minimal approach.  With any luck, that is all that will be needed.

Written by: Carlo Laforge, Heritage Conservation Adviser.

Exterior Rehabilitation and Restoration of Old St. Stephen’s College

Historic photo of Old St. Stephen’s College circa. 1915.

After about three years, the Old St. Stephen’s College – Provincial Historic Resource has now completed the planning and implementation of its exterior rehabilitation and restoration project which started a number of years back with its cedar shingle roof replacement.

This recently completed scope involved foundation upgrades and stair revisions to the ground level access points of the building, including the addition of a compatible, distinguishable and subordinately designed barrier-free access ramp, as well as masonry repairs and the replacement of the 1980’s metal storms with more historically appropriate wooden units that will have the added benefit of allowing more natural ventilation in the building. Additional work also included the rehabilitation of the former fire exit door openings, the return of the round window at the top level of the building and the addition of vented caps to the non-functional chimneys. Read more

New Heritage Conservation Advisory Service Areas and Grant Deadlines for 2014!

Happy New Year everyone! With 2014 underway, I thought that it would be a good idea to provide a little update on the Heritage Conservation Advisory Services Program.

The Heritage Conservation Advisory Services Program provides technical advice and information to the owners or stewards of historic buildings on how best to maintain and conserve their historic resources. A Heritage Conservation Adviser will help you apply the Standards and Guidelines for the Conservation of Historic Places in Canada to your project, regardless of whether or not the building is designated.

In addition to providing free conservation advice, Heritage Conservation Advisers develop the recommendations to approve alterations to Provincial Historic Resources or Registered Historic Resources on behalf of the Minister of Culture. Owners of Registered or Provincial Historic Resources need ministerial permission, under the Historical Resources Act, before altering or repairing their property. Municipal Historic Resources require the permission of their municipality.

Heritage Conservation Advisory Services Program -- H.C.A. Regions of Responsibility (Nov 2013)
Heritage Conservation Advisory Services Program — H.C.A. Regions of Responsibility (Nov 2013)

Please take a look at the attached map. We have changed the boundaries of the areas that individual Heritage Conservation Advisers cover. We re-draw the boundaries now and again based on the location of expected or ongoing heritage conservation projects in Alberta so as to try and share our work load equally and consequently serve our clients better.

Owners or stewards of municipally or provincially designated historic resources must consult with a Heritage Conservation Adviser before undertaking any work that they intend to seek financial assistance for from the Historic Resource Conservation grant program. This is to ensure that eligibility requirements are met and to advise on the most effective way to take advantage of this program.

The Historic Resource Conservation grant program is operated by the Alberta Historical Resources Foundation’s Heritage Preservation Partnership Program. The next application deadline for eligible conservation projects is Monday February 3rd, 2014. The Foundation will award a second batch of grants this fall. The deadline for applications for the fall grant cycle is Tuesday September 2nd, 2014.

Please do not hesitate to contact the Heritage Conservation Adviser for your area with any questions. We will do everything possible to help you, the owner or steward of a piece of our built heritage, to make the most out of your historic place. It is always our pleasure to hear from you.

Written by: Carlo Laforge, Heritage Conservation Adviser.

Why Architects?

To help in planning of course!

In an earlier post, I talked about the importance of proper planning before undertaking work on a designated historic resource. Throughout my career, I have discussed, planned and observed many different types of projects involving modern and historic buildings. I have worked on simple maintenance projects, such as roof replacements or re-painting, and more elaborate ones, such as restorations and additions.

Providing advice to heritage building owners is the most enjoyable part of my work as a conservation adviser. Nevertheless, the size and scope of some projects are quite large. Buildings are made of a variety of materials, like stone, brick and wood. Skilled tradespeople, such as masons, carpenters and electricians know how to care for each material (or building system). Historic building conservation usually draws on the expertise of an exceptionally wide variety of skilled tradespeople. Making a plan to address problems with any major component requires a group of skills that only architects possess. This is why architects can be so helpful.

A project’s size or complexity should not discourage you. I recommend hiring an architect to help identify, prioritise, and cost the required conservation work on any large project. The architect’s report, often called a “conservation plan,” is invaluable. The plan will explain the problem, propose possible solutions and is a useful reference should the work need to be phased out over time.

Hiring an architect is just like hiring any other professional: just as some contractors are not familiar with the principles of heritage conservation (described in The Standards and Guidelines for the Conservation of Historic Places in Canada), some architects are not skilled in this area either. Fortunately, my fellow Heritage Conservation Advisers and I can help you plan a heritage conservation project (call us), which can include advice on how to hire the right architect.

Although hiring architects cost money, the benefits make it worthwhile. Architects know how to analyse a building for problems, they can propose creative solutions and help you select and supervise the right tradespeople. This is why architectural and engineering services have their own grant category within the Alberta Historical Resources Foundation’s Historic Resource Conservation program.

Not all projects or interventions require the services of an architect, but having the planning and scope of work established by contractors alone on large projects can lead to a bad outcome. Having a uniform and properly outlined conservation plan developed by an architect (or engineer, depending on the problem) makes it easier for conservation advisers to approve projects and for contractors to provide accurate cost estimates.

Don’t feel overwhelmed by large conservation projects. It’s true what Steve Smith said at the end of every episode of his Red Green Show.

Written by: Carlo Laforge, Heritage Conservation Adviser.

Can’t Touch This!

Misunderstandings about alterations to designated historic resources

Now and again, I receive a call or a question from someone who appears to be under the impression that their Provincial or Municipal Historic Resource cannot be “altered” and that it must be “preserved” as is.  That is not entirely true.  Under Alberta’s Historical Resources Act, “no person shall destroy, disturb, alter, restore or repair any historic resource…without the written approval from the minister (Section 20-9)” if the site is a Provincial Historic Resource.  For Municipal Historic Resources, the written approval must come from “the council or a person appointed by the council for the purpose (Section 26-6).”  To obtain a written approval, the proposed alteration must be evaluated under the Standards and Guidelines for the Conservation of Historic Place in Canada.

The Standards and Guidelines is a pan-Canadian document that is used as a tool to evaluate and sometimes enforce certain principles in the conservation of our historic resources.  There are four major components to the document: the conservation decision-making process, the conservation treatments, the standards, and the guidelines – with each component going into more and more detail.  The most critical of these is the “conservation decision-making process”.  This process involves three stages that I like to refer to as the acronym U.P.I. (pronounced whoopee!) or Understanding, Planning, and Intervening.

The designation of a historic resource implies that we are trying to conserve it for future generations as part of our shared heritage.  Understanding why a designation was put in place is the first step in determining what can and can’t be touched.  This is summarised in a Statement of Significance (SoS).  Each designated historic resource has one.  If you do not know what the SoS for your designated building contains, you can search for it on the Alberta Register of Historic Places.

Planning is the most important part of any project and for historic resources it is critical in order to avoid mistakes and the potential damage or loss of heritage fabric – usually listed as character-defining elements within a SoS.  As a Heritage Conservation Adviser, it is part of my job to help you understand and plan (and subsequently recommend approvals for Provincial Historic Resources) for projects that will affect your historic resource before any intervening occurs.  When someone indicates to me that they will be going straight to an intervention (i.e. actual physical alteration to a historic resource) without any understanding or planning having taken place, I will tend to react like the guy in this video clip.

Ok, well maybe on the inside.  Suffice it to say, that intervening without understanding or planning is not recommended.  Although I did find the guy in the video’s treatment of the new homeowner’s lack of respect for their heritage building interesting – would you agree?!

Written by:  Carlo Laforge, Heritage Conservation Adviser.

You don’t live in a cave—so why the stalactites?

Ice damming challenges

Darn Ice-Damming.

It’s been a long winter, but summer is almost here. The lengthening days signal that it is time to start planning some of the regular maintenance every building needs to deal with the winters still to come. Have you noticed long, heavy icicles hanging from your home’s eaves this winter? If you did, the building likely has a problem with ice damming. Examining the damage, effecting repairs and solving the underlying problem should be a priority.

Ice damming happens when warm air that rises in a building suddenly hits the frozen roof. Any snow or ice sitting on that roof melts and runs towards the eaves—where it promptly freezes again. That ice plugs the eavestroughs, overflows (hence the icicles) and is often forced into the roof itself. Many think that icicles hanging from the eaves are beautiful, but the water forced into the roof can wind up in the ceiling and walls. Ice damming is often the root cause of problems with mould, rot and even structural failure.

There are several ways to minimise ice damming. Keeping snow off the roof prevents it from melting in the first place. Heat cables can be installed at the base of the roof to prevent water from refreezing at the eaves. However, if the roof is nearing the end of its useful life and in need of rehabilitation, this is an opportunity to address the underlying problem.

Ice damming is indeed a symptom of a larger problem with the roof. Those long, heavy icicles are a sign that a roof lacks proper insulation or ventilation. The more heat escaping from the attic, the more quickly the snow on a roof will melt. The more poorly ventilated the roof is, the less likely the rising heat will dissipate evenly.

What to do? Careful observation and a little research is always the first step: you cannot solve a problem you don’t understand. Get into the habit of comparing the amount of snow on your roof to the amount on the roofs of other buildings in the area. If snow disappears more quickly from your roof, that could be evidence of poor insulation. If the amount of snow is unevenly distributed a few days after a snowfall, your roofing system may be poorly ventilated.

How to fix the underlying problem? Since ice damming is caused by melting snow that quickly refreezes, a solution will limit the amount of heat escaping through the attic while distributing the heat that does inevitably escape evenly across the roof. Be careful—adding too much or the wrong type of insulation or installing it poorly creates its own problems.

Insulating a roof in the wrong way can easily compromise the ventilation. The areas where a roof meets the walls will always be warmer than the peak. Proper ventilation moves heat from the warmer to the cooler areas of the roof, limiting the potential for the snow and ice to melt. In older homes, a lack of ventilation is quite common: exposed rafters or decorative boxed-in soffits with crown mouldings often restrict air flow within the attic. There are ways to improve ventilation that do not comprise the heritage value of your home.

It’s always a good idea to consult a professional. An architect or roofing engineer can help you evaluate the benefits and drawbacks of different solutions. You must consider all of the variables and materials that compose a roof before implementing a solution:a roof is not just a layer of shingles but a system complete with external and internal components.

Written by: Carlo Laforge, Heritage Conservation Adviser.

We’re Cracked!

The Challenge of Fixing Foundation Flaws 

Foundation Problems (minor)Every building has a foundation, whether it’s above ground or below ground, concrete or wood.  A foundation is the first building element constructed and therefore it is very important to get it right.  Any errors or flaws will manifest, either relatively quickly for a major mistake or over time for a subtle error.

In Alberta, most heritage building foundations are poured-in-place concrete.  Some foundations are comprised of concrete blocks while others are comprised of a mixture of masonry units (i.e. fieldstones, cut stones and brick).  Now and again flaws such as cracks and spalling (the breaking or splitting of surface layers) manifest themselves.  It is not recommended to ignore these deficiencies as, depending on their severity, they can be repaired fairly easily.  If left unrepaired, the severity will increase.

Some foundation flaws/cracks are inevitable and often show up early once the building is finished and the full weight of the structure is at rest.  Others appear once the structure above and the ground beneath have fully settled.  Depending on the ground composition and the depth of the foundation (foundation depths vary, such as a full basement vs. a crawlspace), these settlement cracks will vary in size.  And finally, some cracks will suggest that something is wrong with the foundation but if addressed in a timely manner may still allow a reasonable/affordable correction to be implemented.

Foundations can also be damaged by water and seasonal frost heaving.  To minimise this damage, ensure that the grade slopes away from the building with sufficient drainage to move the water away.  Frost protection can be achieved by embedding the ground with high-density foam insulation to prevent the frost line from going under the foundation if it is less than four or six feet (1.2 metres or 1.8 metres) or by underpinning the foundation to a depth greater than the frost level in the area (this is usually at least 1.8 metres in Canada, which is one of the reasons why we tend to have basements).  If one has to dig that far down to protect the foundation against frost then one might as well as make it a usable space.

The Standards and Guidelines for the Conservation of Historic Places in Canada  contains a number of sections related to the conservation and repair of foundations: check out the general recommendations of “Structural Systems” (4.3.8) under “Guidelines for Buildings” and for material specific information read about “Masonry” (4.5.3) and “Concrete” (4.5.4) under “Guidelines for Materials.”  Depending on the type of structure and level of intervention, other sections of the Standards and Guidelines might also need to be reviewed.

The following images summarize some of the types of foundation cracks and the potential solutions that might be proposed:

Type of crack: Minor – surface only, usually located at higher stress points.
Type of crack (minor): surface only, usually located at higher stress points.
Proposed Solution: Minor  - Concrete patching, parging or an injected filler product
Proposed solution (minor): concrete patching, parging or an injected filler product.
Type of crack: Medium - showing signs of structural failure and weakness such as spalling.
Type of crack (medium): showing signs of structural failure and weakness such as spalling.
Proposed Solution: Medium - Containment – pour new foundation wall against the old to stop the structural failure.
Proposed solution (medium): containment – pour new foundation wall against the old to stop the structural failure.
Type of crack: Significant - structural failure has occurred and structure becoming increasingly unstable.
Type of crack (significant): structural failure has occurred and structure becoming increasingly unstable.
Proposed Solution: Significant - Full foundation replacement.
Proposed solution (significant): full foundation replacement.


  • Minor and some medium types of cracks can usually be repaired by foundation specialists.
  • Some medium and all significant level cracks will require the services of a structural engineer.
  • Due to the specialty of the mixes and structural nature of foundations it is best to seek certified and experienced masonry/concrete professionals to help resolve the situation.

Ultimately, foundations perform a crucial function for our buildings.  Whatever problems occur they will begin to transfer to the rest of the structure if they are not addressed.  For designated provincial and municipal historic resources the costs incurred to address these issues, whether they be minor, medium or significant (including any engineering costs), would be eligible for grant funding through the Alberta Historical Resources Foundation’s Historic Resource Conservation program.

Written by: Carlo Laforge, Heritage Conservation Adviser.